/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.numbers.field;
  
  import org.apache.commons.numbers.core.NativeOperators;
  
  /**
   * Wraps a {@code double} value in order to be used as a field
   * element.
   */
  public final class FP64 extends Number
      implements NativeOperators<FP64>,
                 Comparable<FP64> {
      private static final long serialVersionUID = 1L;
  
      /** Additive neutral. */
      private static final FP64 ZERO = new FP64(0);
      /** Multiplicative neutral. */
      private static final FP64 ONE = new FP64(1);
      /** Value. */
      private final double value;
  
      /**
       * @param value Value.
       */
      private FP64(double value) {
          this.value = value;
      }
  
      /**
       * Factory.
       *
       * @param value Value.
       * @return a new instance.
       */
      public static FP64 of(double value) {
          return new FP64(value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 add(FP64 a) {
          return new FP64(value + a.value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 negate() {
          return new FP64(-value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 multiply(FP64 a) {
          return new FP64(value * a.value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 reciprocal() {
          return new FP64(1 / value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 subtract(FP64 a) {
          return new FP64(value - a.value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 divide(FP64 a) {
          return new FP64(value / a.value);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 multiply(int n) {
          return new FP64(value * n);
      }
  
      /** {@inheritDoc} */
      @Override
      public FP64 pow(int n) {
          if (n == 0) {
             return ONE;
         }
 
         return new FP64(Math.pow(value, n));
     }
 
     /** {@inheritDoc} */
     @Override
     public boolean equals(Object other) {
         if (other instanceof FP64) {
             final FP64 o = (FP64) other;
             // Allow -0.0 to equal 0.0
             return Double.doubleToLongBits(value + 0.0) == Double.doubleToLongBits(o.value + 0.0);
         }
         return false;
     }
 
     /** {@inheritDoc} */
     @Override
     public int hashCode() {
         // Same hash code for -0.0 and 0.0
         return Double.hashCode(value + 0.0);
     }
 
     /** {@inheritDoc} */
     @Override
     public String toString() {
         return Double.toString(value);
     }
 
     /** {@inheritDoc} */
     @Override
     public double doubleValue() {
         return value;
     }
     /** {@inheritDoc} */
     @Override
     public float floatValue() {
         return (float) value;
     }
     /** {@inheritDoc} */
     @Override
     public int intValue() {
         return (int) value;
     }
     /** {@inheritDoc} */
     @Override
     public long longValue() {
         return (long) value;
     }
     /** {@inheritDoc} */
     @Override
     public byte byteValue() {
         return (byte) value;
     }
 
     /** {@inheritDoc} */
     @Override
     public int compareTo(FP64 other) {
         return Double.compare(value, other.value);
     }
 
     /** {@inheritDoc} */
     @Override
     public FP64 zero() {
         return ZERO;
     }
 
     /** {@inheritDoc} */
     @Override
     public boolean isZero() {
         return value == 0.0;
     }
 
     /** {@inheritDoc} */
     @Override
     public FP64 one() {
         return ONE;
     }
 
     /** {@inheritDoc} */
     @Override
     public boolean isOne() {
         return value == 1.0;
     }
 }